Investigators say a Pontiac van was disabled on the shoulder of Route 29 on Saturday night. The driver, 50-year-old Debra Watson of Silver Spring, got out and was standing on the shoulder of the road. That's when her vehicle was struck by a Volvo. The Pontiac then struck Watson and pushed her into the guardrail.

Police say Watson was transported to Shock Trauma in Baltimore and was in serious but stable condition Sunday.

Police identified the Volvo driver as 58-year-old Daniel Kim of Silver Spring. He was not injured. Police say it appears Kim may have been impaired by alcohol and did not drive in a single lane.